Origin of photoresponse in black phosphorus phototransistors
Abstract
We study the origin of a photocurrent generated in doped multilayer black phosphorus (BP) phototransistors, and find that it is dominated by thermally driven thermoelectric and bolometric processes. The experimentally observed photocurrent polarities are consistent with photothermal processes. The photothermoelectric current can be generated up to a micrometer away from the contacts, indicating a long thermal decay length. With an applied source-drain bias, a photobolometric current is generated across the whole device, overwhelming the photothermoelectric contribution at a moderate bias. The photoresponsivity in the multilayer BP device is two orders of magnitude larger than that observed in graphene.
- Publication:
-
Physical Review B
- Pub Date:
- August 2014
- DOI:
- 10.1103/PhysRevB.90.081408
- arXiv:
- arXiv:1407.7286
- Bibcode:
- 2014PhRvB..90h1408L
- Keywords:
-
- 73.21.-b;
- 73.22.Lp;
- 73.61.-r;
- 74.78.Fk;
- Electron states and collective excitations in multilayers quantum wells mesoscopic and nanoscale systems;
- Collective excitations;
- Electrical properties of specific thin films;
- Multilayers superlattices heterostructures;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- Phys. Rev. B 90, 081408R (2014)